It is said that negatives play an important part in Chaucer's texts, to say nothing of other Middle English writings. The scholars only deal with the syntactic or grammatical use of negatives, but no one has yet explained the meanings of negative expressions. This paper, focusing on the speech of the characters, has investigated the negatives or negative expressions used in the speeches of the main characters Walter and Griselda and the Narrator in "The Clerk's Tale," The Canterbury Tales. It should be noted here that the relationship between master and man cultivated and established "gladly" in "The General Prologue" is transferred to the conjugal relationship between Walter and Griselda in "The Clerk's Tale." Gnselda, using negative expressions, receives Walter's ascetic teaching gladly and naturally.